The second series of Channel 4's fabulous conspiracy thriller Utopia got off to a controversial start, though oddly not on account of its usual sphincter-clenching violence (the first series began with someone having his eye removed with a teaspoon), but for playing fast and loose with the murder of Airey Neave, the Tory politician blown up in his Vauxhall Cavalier by Irish republicans in 1979 – a fate repurposed here as the work of an MI5 hit squad bent on silencing him for what he knew about the… well, then it starts to get complicated, and not just in an ethical way.

If you were bewildered by the plot of the first series but loved the shrieking colours and beautiful camerawork and fizzing young characters on the run from psycho gunmen and gassers, this double-header over successive nights – the first part a useful prequel – was another chance to find out, or at least guess at, who was really what and why they had done what they seemed to have done. Opening in the bilious light of the late 1970s we learned more about the Network, the global black ops organisation whose plan to tackle world overpopulation – as opposed to killing people one by one – involved engineering a virus that could "switch off" human reproduction in all but those best genetically equipped to carry us into the future. Were we talking about race? On the contrary, said Philip, the scientist behind it (Tom Burke, behind a 70s beard), it would be a world without race. This was just what the glamorous young MI5 woman (Rose Leslie as an earlier version of Geraldine James's Milner) in charge of random slaughter wanted to hear, though that was before Philip got cold feet. Before long he was feverishly embedding the squiggles of his doomsday formula into the manuscript of a graphic novel (the McGuffin of the first series), having taken the precaution of injecting his four-year-old daughter Jessica (Aine Garvey – an uncanny match with her later self) with the real thing – thus unwittingly (I assume) rendering her a target for the Network after his suicide in a psychiatric clinic. I should say Philip wasn't the most successful parent, what with the psychological experiments he had already conducted on his son, who then grew up to be deadpan killer Arby (the excellent Neil Maskell), a blunt instrument for the Network who spent most of the last series asking people, "Where is Jessica Hyde?" as a prelude to replastering the wall with their brains.

Did I say "useful prequel"? I didn't feel all the answers were quite there (even if the missing ones were those I'd forgotten the questions to) but it made me want to go back to last year and start again. By now, though, part two was upon us, with stoical bug-eyed supergirl Jessica the elder (Fiona O'Shaughnessy) now behind bars and resisting Milner's attempts to torture one last crucial detail out of her before the Network's forthcoming "V-Day", when most of the world will be sterilised under cover of a mass Russian flu vaccination. Will she escape soon? It looked like it, having ingeniously hanged her interrogator with a rope made of pages from the Bible and equipped herself with a spring from his ballpoint pen. Meanwhile, here too were our young friends – bored Ian from IT and feral boy Grant, the two of them catching up with sweary Welsh girl Becky in a warehouse swarming with MI5 swat men, two frantic scientists (one of them played by Kevin Eldon having, I'm afraid, the funniest heart attack in TV history) – and the great Arby, newly humanised and, better late than never, a force for good. Welcome back, all. The clock, as they say, is ticking.

This was all a far cry from the world of Glasgow Girls, an inspiring BBC3 musical drama based on the true story of a bunch of ordinary comprehensive pupils who fought the Home Office to prevent their schoolfriend Agnesa and her refugee family being deported to Kosovo in 2005. It started as a classroom strike and then moved outside, with petitions and community meetings. Not every resident was crazy about the idea of helping asylum seekers, but one after another the girls – feisty young weegies, but also Roma, Somali and Iraqi, fearful that they would be next – were on their feet. How could the government send these families all the way to Scotland, wait for their kids to settle into school, then arrive mob-handed at dawn after a couple of years to kick down the door and drag everyone away in handcuffs? The community were soon marching in the street and organising early-warning systems against police raids, while the students and their teacher Mr Girvan (Gary Lewis, evoking a Scottish Bob Hoskins) bombarded the authorities and media with demands for fairness and justice. Did I say there was singing too? It was all very rousing. Setbacks intervened but then triumph! Who could fail to cheer at the final freeing of Agnesa and her folks from the unattractive-sounding Yarl's Wood Immigration Removal Centre in Bedfordshire, and their tearful Glasgow reunion. Human beings doing what they do best. You can't beat it.

Silicon Valley: 'its characters struggled to gel'.

Two comedies caught the eye last week. HBO's Silicon Valley – about a shoe-gazing genius and his computer misfit chums setting up a new tech business – promised a collision between The Social Network and Entourage, with maybe a touch of The Big Bang Theory. Ah, if only. It was sharply enough written (by Mike Judge, creator of Beavis & Butt-head), and its rags-to-riches premise offered momentum, but the characters (innocents versus hardasses) struggled to gel in this opener. I don't think it helped to have a protagonist so designedly lacking in charisma, or that the drama relied on guys sitting around a screen exclaiming: "He's somehow worked out how to do a search on a compressed data space!" Perhaps it will get better. It arrives with rave reviews from the States.

Jo Hartley as Jean and Terry Mynott as Martin Hurdle in The Mimic: 'endearing rather than hilarious'. Photograph: Hal Shinnie

I do have a soft spot for The Mimic, back for a second series, with luckless Martin (Terry Mynott) having lost his job as a litter collector at the same time as failing to get one as a professional entertainer on TV. Not a great deal happens in this show and it entirely lacks conflict. Accordingly, we saw Martin go to the job centre, then try his hand doing his voices as a street performer (Al Pacino, Ronnie Corbett), egged on by his droll newsagent friend played by Neil Maskell (see Arby above). Their other friend Jean bought a pink car. It's endearing rather than hilarious, which isn't always a good sign. But you can tell the characters like one another, and I suppose it's just catching.